Umaima is 4 times as old as Nadia and is also 27 years older than Nadia. How old is Umaima?
Answer: We can use the given information to write down two equations that describe the ages of Umaima and Nadia. Let Umaima's current age be $u$ and Nadia's current age be $n$ $u = 4n$ $u = n + 27$ Now we have two independent equations, and we can solve for our two unknowns. One way to solve for $u$ is to solve the second equation for $n$ and substitute that value into the first equation. Solving our second equation for $n$ , we get: $n = u - 27$ . Substituting this into our first equation, we get the equation: $u = 4$ $(u - 27)$ which combines the information about $u$ from both of our original equations. Simplifying the right side of this equation, we get: $u = 4u - 108$ Solving for $u$ , we get: $3 u = 108$ $u = 36$.